Banker’s Algorithm Implementation in CPN Tools

When constructing discrete simulation models of complex transportation systems, their designers face problems of deadlock states occurring in the course of simulation. When analyzing it, the issue was transformed to a problem of solving deadlock states in resource allocation systems (RAS) with non-sequential processes with flexible routing and use of resources of multiple types at once. As a suitable deadlockavoidance policy, the banker’s algorithm (BA) has been chosen. The task was to modify the basic version of the BA and to test the developed algorithm on a sample transportation system with the outlined properties. As a suitable environment for this, the CPN Tools were chosen, what led to an implementation of the modified version of the BA in the CPN ML, language used by the CPN Tools. The paper explains modifications of the algorithm, describes an implementation of it in the CPN ML and shows its use on a coloured Petri net model of a small example from the outlined category of the RAS.